In an interpretive work, Thomas M. King undertakes an analysis of twelve major Western philosophers in terms of Jung's four functions: S/N T/F (King, 1999). The general significance of these categories for describing philosophical thought are listed below:

S: Sensing philosophers are likely to view the world as nothing more than the totality of independent units (building blocks). Each unit or entity is separate unto itself, and has no significance beyond itself.

N: Philosophers strong in intuition view the world as a supreme synthesis. Individual objects and entities have little or no identity in themselves, but exist only in relation to the unified whole.

T: Philosophers who are dominant for thinking will view the world as a precise system within which everything can be deduced. The world functions like a great equation.

F: Feeling-led philosophers view human beings and their relationships in concrete terms as the ultimate reality. They seek solutions within which all people and things have their proper place.

These Jungian concepts enable us to roughly categorize philosophical orientations, but that is not Thomas King’s ultimate goal. He seeks to understand the development of a philosopher’s main ideas over time. More specifically, his aim is to show how the development of each philosopher's work can be understood using the Jungian concept of individuation.

Jungian individuation involves a journey or progression from an younger stage to a more mature state. In the younger stage, an attempt is made to comprehend and manage life using the dominant function, and eventually the auxiliary and third functions. For various reasons, the inadequacy and emptiness of this approach becomes clear over time, and a quest to find and integrate the missing fourth function is undertaken. The dominance relations between Jungian personality functions are covered in the catalog entry for the Myers-Briggs Type Indicator.

King uses this journey of individuation as a framework for interpreting the philosophical development of Plato, Augustine, Descartes, Spinoza, Locke, Hume, Kant, Rousseau, Kierkegaard, Sartre, Teilhard and Whitehead. While his study does not elucidate any new explicit models of the structure of concern, it remains of interest for the present work. Models of the structure of concern have so far been proposed to illuminate business and management behavior, personality dynamics and learning styles. If they have this value in the present, they may have it for historical subjects as well. King's work is a useful first foray in this direction.

King's analysis of each philosopher's development is engaging, but I will not summarize it here. In the interest of economy, I will simply outline some of the ways the structure of concern is traced by King in the works of Plato, Descartes, Locke, Spinoza and Kant. The reader is referred to King for the full treatment of this subject.

Looking only at Plato’s Republic, he describes the four virtues of the state and the four virtues of the soul, as well as the four studies or disciplines that cultivate these virtues. They are listed below, with the dominant function marked.

It is interesting that in the Republic, three of the virtues are seen as relatively easy to grasp, but the fourth is mysterious and bewildering, requiring the exhaustive exploration of a concrete example to render it comprehensible.

The rationalist philosophy of Descartes required several sharp delineations between Jungian functions, most notably between Sensing and Thinking, one of which was highly doubtful (Sensing), one of which was less so (Thinking). He further distinguished between thinking and imagination (the Jungian Intuition) and memory which is both a source of and an amplifier of Feeling. Descartes’ project consists in no small part of establishing the dominance of Thinking and its autonomy with respect to the other functions.

Descartes
S – Sensation
N – Imagination
T – Thinking
F - Memory

As one of the British Empiricists, Locke is easy to position as a Sensing dominant philosopher. In his Essays on the Laws of Nature, he contrasts sense-experience with inscription or received codified knowledge (Thinking) and tradition (Feeling). He also adds that there is a fourth function of supernatural knowledge and divine revelation (Intuition), which he excludes as irrelevant to his project. So thorough is his exclusion of tacit and synoptic information that he runs into major problems in his empiricism, finding it impossible to conceive of forces that might bind particulate bodies into unified wholes, so strong is his commitment to the sensate perspective.

Spinoza attempted the deduction of an entire philosophy using methods resembling those used in geometry, arguing from first principles and axioms. This is clearly a Thinking-dominant project. His early works include discussions of four different models of perception: perception from random experience, perception from inference over incomplete information, perception of a thing through its pure essence or through knowledge of its proximate cause, and perception based on report, communication, memory or conventional sign.

Kant, as yet another European rationalist, expresses a very clear Thinking dominance. His triumvirate of faculties in the Critique of Pure Reason; namely Reason, Understanding and Sensation, map very naturally onto the Jungian categories of Thinking, Intuition and Sensing, respectively. Feelings are described as pathological in the Critique of Practical Reason, detracting from the purity of duty and enslaving people to their appetites.